too free use of alcohol is a loss of appetite and an impaired power of digestion. Now, the effects of the opiate plan of treatment, conducted with the precautions to which I have before alluded, are in most respects the opposite of those produced by alcoholic stimulants; for we seek, by means of opium, a natural remedy for fatigue, that remedy being sleep, which brings with it a desire for food, and the power to digest it. Alcohol is taken for the sake of the immediate stimulus ; the subsequent depression is the drawback upon its utility as a means of keeping up the working powers. The object in giving opium is to obtain, not its stimulant effects, which are comparatively slight and transient, nor immediately its composing influence, but the refreshment which follows the latter, and which has nothing corresponding with it among the ordinary consequences of alcoholic stimulants.

My objections to the abuse of alcohol as a stimulant do not of course apply to the use of wholesome wine and beer as articles of diet by those who require them, and who appear to derive benefit from them. Moreover, there are certain cases of nervous dssease in which some form of alcoholic stimulant may be given with great advantage, either alone or in conjunction with opium. I refer to cases of extreme restlessness, either with or without delirium, and whether resulting from intemperance or from grief, or watching or fatigue, when the bodily powers are very feeble, although under the mental influence there may be great excitement. In these cases, repeated large doses of opium sometimes fail to procure sleep, but appear rather to have a depressing influence: the patient's skin becomes cold and is bathed in perspiration, while the delirium and excitement continue. In such circumstances, the continued use of the opium is not only useless, but injurious and dangerous, and the surest mode of arresting the collapse, and of procuring sleep, is to give freely either wine or brandy, or, in cases of intemperance, the stimulant to which the patient has been accustomed, with beef-tea or some other form of nourishment.

It is scarcely necessary to observe, that in all cases of nervous disease we must carefully watch the signs of functional disturbance or of structural change in any organ of the body, and that we must meet such symptoms by the appropriate remedies. And although, in most instances, a tonic plan of treatment is required, yet we must not hesitate to resort to measures of depletion if they are called for by the occurrence of such organic disease as appears to need this treatment.

The cases which are least favourable either for the opiate or for any other plan of treatment, are:-1st, cases of confirmed hypochondriasis or melancholy of very long duration, and especially when these have the character of religious despondency; 2ndly, cases in which extreme nervousness has resulted from great terror, or from a sudden shock which has left a deep and durable impression upon the mind and nervous system; and, lastly, cases in which the symptoms are perpetuated by some constant source of anxiety and sorrow.

These classes of cases, although very unfavourable, and often little benefited by any plan of treatment, whether medical or moral, are yet by no means hopeless nor always incurable. Their unfavourable and unmanageable character is, however, greatly confirmed when they are complicated with epilepsy; and this whether the epilepsy has been induced by a sudden shock of grief or terror, or whether it has supervened upon long-continued anxiety and nervousness.-Medical Times and Gazette, Oct. 22, 1853, p. 415.

24.-On the Diagnosis of Cerebral Diseases. By DR. ROBERT HUNTER SEMPLE.-The following is a summary of the chief points of diagnostic importance respecting discases affecting the skull and the cerebral membranes:]

1. When a person suffers from constant and dull pain in the head, with or without convulsions, the pain being limited to a certain region, the external surface of the head being cool and the pulse regular, the digestive system not much or not at all disturbed, and the intellect unimpaired; if any thickening of the bony structure can be perceived, or if the patient has suffered from syphilis, it may be conjectured as probable that there is thickening of the skull, and that the symptoms are due to that cause. In such a case, a moderate diet should be enjoined; leeches may be occasionally employed; the bowels should be kept gently open; but I think our chief reliance should be upon the internal administration of iodide of potassium in increasing doses, and continued for a long period.

2. When there is pain and heat of the head, vomiting, nausea, want of appetite, foul tongue, derangement of bowels, rapid and full pulse, squinting, delirium, thirst, and subsequent coma, and if the blood drawn be buffed and cupped, there can be little doubt that the case is one of meningeal inflammation. In such a case, there is no time to be lost; the warm bath must be used in the case of a child; cold must in all cases be applied to the head; leeches are always necessary; calomel is to be freely administered, and alterative aperients must be given at the same time. By the adoption of such measures many valuable lives may be saved.

3. When the head is cool, the pulse moderate, the tongue clean, the motions healthy, then, although there may be the most violent and long continued convulsions, squinting, drawing in of the thumbs towards the palms of the hands, and all other symptoms indicating deranged action of the nervous centres, there is nevertheless an absence of serious centric disease. We may here reasonably hope for a favourable termination by the use of ordinary hygienic means; such as lancing the gums, if the patient be undergoing the process of dentition; attending to the quality of the breast-milk in very young infants; correcting any acescences in the primæ viæ; change of air,

and the judicious use of stimulants and tonics; and the adoption of all such other means as are calculated to improve the powers of the system in general.

It cannot be urged in too strong terms, that the mere existence of convulsions, however alarming they may appear, does not indicate, alone, a serious disease of the brain; these movements are merely the external manifestations of cerebral irritation, and are often caused by circumstances comparatively trivial. On the other hand, it must be remembered that, at all periods of life, the cerebral membranes, especially the pia mater, are apt to take on inflammatory action; and that, slight and web-like as this membrane is, and insignificant in appearance as are the lesions which it exhibits to the scalpel or to the microscope, yet upon its integrity or its unsoundness often depends the brightness, the perversion, or the obscurity of the intellect; and that an inflammatory disease of its texture is one of the most frequent causes of death. The most energetic treatment often fails to rescue the patient from the grave; but it is nevertheless of paramount importance to detect the malady during life, and, if possible, to arrest its progress.-Association Med. Journal, Dec. 2, 1853, p. 1055.

25. ON THE ORIGIN AND CIRCULATION OF THE
NERVOUS INFLUENCE.

By DR. JOHN M. STRACHAN.

[In spite of all the talent displayed in the investigation, it is undecided whether the nervous influence is identical with galvanic electricity or not. We should first decide whence this influence is derived. Some say it is generated in the brain and nervous masses, and distributed by the nerves; but the fact is, that there is scarcely any tissue less likely to originate electricity than the substance of which these nervous masses consists. Dr. Strachan suggests the idea that it is produced by the chemical action which is constantly going on in the change of arterial into venous blood. He observes:]

In every chemical action galvanic electricity is evolved; a large amount must therefore be produced in the animal system by the change of arterial into venous blood. The following is a condensed view of what is now generally admitted to be the nature of the change referred to. The blood after being exposed to the influence of the atmospheric air in the lungs, acquires a large amount of oxygen, so that the iron which it contains exists in the highest state of oxygenation as the peroxide. On reaching the capillaries, the peroxide of iron comes in contact with carbon, which attracts a portion of the oxygen; by this the peroxide is reduced to the state of protoxide of iron, and the carbon is converted into carbonic acid. The protoxide of iron and the carbonic acid, thus produced, immediately unite, forming the carbonate of iron.

It is quite clear that by these combinations galvanic electricity must be produced in great abundance; and as iron does not enter into the composition of any of the tissues or secretions of the body, it is probable that the production of electricity is the only purpose of this mineral existing in the blood in such quantity.

The chemical changes referred to are effected in the vessels situated between the termination of the arteries and the commencement of the veins. Now it is demonstrable that wherever arteries terminate and veins begin, there also are nerves distributed, and as these consist of afferent and efferent fibrils, which have been proved to be conductors of electricity, we have only to suppose that the galvanism set free by the chemical action is taken up by the afferent nerves, and passing through the nervous centres, is returned by the efferent nerves to the same point, and thus a continued electric circuit is established, every modification of which must promote or retard the chemical change, and so influence the circulation of the blood; and, on the other hand, changes in the circulation of the blood must have a powerful influence in modifying the electric current. There is thus a constant circulation of nervous fluid dependent upon the circulation of the blood; and just as the heart does not generate, but only distributes the blood, so the brain and the other nervous centres do not produce, but serve to accumulate, modify, and distribute the nervous influence.

This constant circulation of nervous fluid, in union with the circulation of the blood, is sufficient to give us an idea of organic life; and, perhaps, in some of the lower forms of animals this is all that exists. But as we rise in the scale of organization, the animal system becomes a much more complicated machine, having a variety of functions. It is therefore necessary to inquire how these may be performed.

The experiments of various inquirers have rendered it probable that there are distinct nervous centres, and that to each of these belongs its own separate function. It is probable that these functions are performed, not as has generally been explained, by electric shocks communicated from or transmitted to the central organs, but by sustained and constant circuits of electricity produced by the changes of the blood in the capillaries, and by the modification of these currents by external or internal agencies.

On the supposition that the different nervous centres have separate functions, and that they all receive their electricity from the chemical changes of the blood, there comes the question whether each central organ has a completely distinct set of nerves, and that thus there are distinct nervous extremities, as well as distinct centres, for each function; or whether there is only one afferent and one efferent fibril accompanying each capillary of the arteries and veins, which, receiving the electricity, conveys it to the nearest ganglion, from whence it is partly returned to the same point, thus maintaining the life of the part; but that a portion of the electricity is transmitted along other nerves to the more distant central organs, thus forming a longer circuit of motion or sensation.

It seems to be an universally received opinion that sensation results from impressions transmitted by the nerves to the central organ; that motion on the other hand, arises from an influence sent from the central organ to the extremities of the nerves, thus conveying the idea that these centres are more sentient and more capable of originating motion than the other parts of the nervous system. This idea of impressions being conveyed to and from the brain is contrary to our consciousness, and this should be a powerful reason for doubting its truth. When I prick my finger, I am not conscious of any impression being transmitted to the brain; on the contrary, I perceive the impression in the finger, and only there. Why then, should we suppose that we are conscious only of impressions that are conveyed to the brain? It is true that any obstruction in the nerves connecting the external organs with the brain destroys sensation or motion. But this only shows that, for these functions to be performed, it is necessary that the electric circuit should be uninterrupted. The mind, however, is as likely to perceive any modification of that circuit at the point where it occurs, as at the distant central organ. And in the same way motion may arise from some change effected at the extremities of the nerves, and not from an influence transmitted from the brain.

Regarding those operations which are considered as mental, I would merely hazard a conjecture—namely, that the large development of the cerebrum should not be considered as a central organ, but as a development of peripheral nerves receiving electricity from the capillaries of the blood-vessels of the brain, and that these nerves have their centre in the commissures. This organ, which thus consists entirely of nerves and blood-vessels, may be, in accordance with general opinion, the seat of mental operations.

If it were established that there is a constant circulation of the nervous fluid, such as has been described, it would render our conceptions of the nervous system as clear as those we possess of the circulation of the blood. The principle which governs it is the same as that of the galvanic battery, or a more apt illustration would be the electric telegraph, with its electricity conveyed by the positive and returned by the negative wire; and to carry out the comparison, the different nervous centres may be considered as so many telegraphic stations. There is this difference, however, that, instead of successive sparks of electricity, we have a sustained and continuous current, and consequently a provision in the circulation of the blood for keeping up a supply of the chemical ingredients necessary to maintain the stream. If it were established that the circulation of nervous fluid is kept up in the manner described, it would improve our knowledge of the circulation of the blood, by showing a purpose effected by it even more important than the nourishment of the tissues; and we should then clearly understand the use of the oxygenation of the blood by respiration to be, the restoration to that fluid of the power of imparting electricity. Lancet, Feb. 25, 1854, p. 210.